namespace gold
{
-class Object;
+class General_options;
+class Relobj;
class Read_relocs_data;
class Stringpool;
+class Symbol;
class Layout;
+template<int size>
+class Sized_symbol;
+
+template<int sh_type, bool dynamic, int size, bool big_endian>
+class Output_data_reloc;
+
// A class to read the relocations for an object file, and then queue
// up a task to see if they require any GOT/PLT/COPY relocations in
// the symbol table.
// SYMTAB_LOCK is used to lock the symbol table. BLOCKER should be
// unblocked when the Scan_relocs task completes.
Read_relocs(const General_options& options, Symbol_table* symtab,
- Layout* layout, Object* object, Task_token* symtab_lock,
+ Layout* layout, Relobj* object, Task_token* symtab_lock,
Task_token* blocker)
: options_(options), symtab_(symtab), layout_(layout), object_(object),
symtab_lock_(symtab_lock), blocker_(blocker)
const General_options& options_;
Symbol_table* symtab_;
Layout* layout_;
- Object* object_;
+ Relobj* object_;
Task_token* symtab_lock_;
Task_token* blocker_;
};
// SYMTAB_LOCK is used to lock the symbol table. BLOCKER should be
// unblocked when the task completes.
Scan_relocs(const General_options& options, Symbol_table* symtab,
- Layout* layout, Object* object, Read_relocs_data* rd,
+ Layout* layout, Relobj* object, Read_relocs_data* rd,
Task_token* symtab_lock, Task_token* blocker)
: options_(options), symtab_(symtab), layout_(layout), object_(object),
rd_(rd), symtab_lock_(symtab_lock), blocker_(blocker)
const General_options& options_;
Symbol_table* symtab_;
Layout* layout_;
- Object* object_;
+ Relobj* object_;
Read_relocs_data* rd_;
Task_token* symtab_lock_;
Task_token* blocker_;
{
public:
Relocate_task(const General_options& options, const Symbol_table* symtab,
- const Layout* layout, Object* object, Output_file* of,
+ const Layout* layout, Relobj* object, Output_file* of,
Task_token* final_blocker)
: options_(options), symtab_(symtab), layout_(layout), object_(object),
of_(of), final_blocker_(final_blocker)
const General_options& options_;
const Symbol_table* symtab_;
const Layout* layout_;
- Object* object_;
+ Relobj* object_;
Output_file* of_;
Task_token* final_blocker_;
};
-// Integer swapping routines used by relocation functions. FIXME:
-// Maybe these should be more general, and/or shared with elfcpp.
-
-// Endian simply indicates whether the host is big endian or not,
-// based on the results of the configure script.
-
-struct Endian
-{
- public:
- // Used for template specializations.
-#ifdef WORDS_BIGENDIAN
- static const bool host_big_endian = true;
-#else
- static const bool host_big_endian = false;
-#endif
-};
-
-// Valtype_base is a template based on size (8, 16, 32, 64) which
-// defines a typedef Valtype for the unsigned integer of the specified
-// size.
-
-template<int size>
-struct Valtype_base;
-
-template<>
-struct Valtype_base<8>
-{
- typedef unsigned char Valtype;
-};
-
-template<>
-struct Valtype_base<16>
-{
- typedef uint16_t Valtype;
-};
-
-template<>
-struct Valtype_base<32>
-{
- typedef uint32_t Valtype;
-};
-
-template<>
-struct Valtype_base<64>
-{
- typedef uint64_t Valtype;
-};
-
-// Convert_host is a template based on size and on whether the host
-// and target have the same endianness. It defines the type Valtype,
-// and defines a function convert_host which takes an argument of type
-// Valtype and swaps it if the host and target have different
-// endianness.
-
-template<int size, bool same_endian>
-struct Convert_host;
-
-template<int size>
-struct Convert_host<size, true>
-{
- typedef typename Valtype_base<size>::Valtype Valtype;
-
- static inline Valtype
- convert_host(Valtype v)
- { return v; }
-};
-
-template<>
-struct Convert_host<8, false>
-{
- typedef Valtype_base<8>::Valtype Valtype;
-
- static inline Valtype
- convert_host(Valtype v)
- { return v; }
-};
-
-template<>
-struct Convert_host<16, false>
-{
- typedef Valtype_base<16>::Valtype Valtype;
-
- static inline Valtype
- convert_host(Valtype v)
- { return bswap_16(v); }
-};
-
-template<>
-struct Convert_host<32, false>
-{
- typedef Valtype_base<32>::Valtype Valtype;
-
- static inline Valtype
- convert_host(Valtype v)
- { return bswap_32(v); }
-};
-
-template<>
-struct Convert_host<64, false>
-{
- typedef Valtype_base<64>::Valtype Valtype;
-
- static inline Valtype
- convert_host(Valtype v)
- { return bswap_64(v); }
-};
-
-// Convert is a template based on size and on whether we have a big
-// endian target. It defines Valtype and convert_host like
-// Convert_host. That is, it is just like Convert_host except in the
-// meaning of the second template parameter.
-
-template<int size, bool big_endian>
-struct Convert
-{
- typedef typename Valtype_base<size>::Valtype Valtype;
-
- static inline Valtype
- convert_host(Valtype v)
- { return Convert_host<size, big_endian == Endian::host_big_endian>
- ::convert_host(v); }
-};
-
-// Swap is a template based on size and on whether the target is big
-// endian. It defines the type Valtype and the functions readval and
-// writeval. The functions read and write values of the appropriate
-// size out of buffers, swapping them if necessary.
-
-template<int size, bool big_endian>
-struct Swap
-{
- typedef typename Valtype_base<size>::Valtype Valtype;
-
- static inline Valtype
- readval(const Valtype* wv)
- { return Convert<size, big_endian>::convert_host(*wv); }
-
- static inline void
- writeval(Valtype* wv, Valtype v)
- { *wv = Convert<size, big_endian>::convert_host(v); }
-};
-
-// Swap_unaligned is a template based on size and on whether the
-// target is big endian. It defines the type Valtype and the
-// functions readval_unaligned and writeval_unaligned. The functions
-// read and write values of the appropriate size out of buffers which
-// may be misaligned.
-
-template<int size, bool big_endian>
-class Swap_unaligned;
-
-template<bool big_endian>
-class Swap_unaligned<8, big_endian>
-{
-public:
- typedef typename Valtype_base<8>::Valtype Valtype;
-
- static inline Valtype
- readval_unaligned(const unsigned char* wv)
- { return *wv; }
-
- static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
- { *wv = v; }
-};
-
-template<>
-class Swap_unaligned<16, false>
-{
-public:
- typedef Valtype_base<16>::Valtype Valtype;
-
- static inline Valtype
- readval_unaligned(const unsigned char* wv)
- {
- return (wv[1] << 8) | wv[0];
- }
-
- static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
- {
- wv[1] = v >> 8;
- wv[0] = v;
- }
-};
-
-template<>
-class Swap_unaligned<16, true>
-{
-public:
- typedef Valtype_base<16>::Valtype Valtype;
-
- static inline Valtype
- readval_unaligned(const unsigned char* wv)
- {
- return (wv[0] << 8) | wv[1];
- }
-
- static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
- {
- wv[0] = v >> 8;
- wv[1] = v;
- }
-};
-
-template<>
-class Swap_unaligned<32, false>
-{
-public:
- typedef Valtype_base<32>::Valtype Valtype;
-
- static inline Valtype
- readval_unaligned(const unsigned char* wv)
- {
- return (wv[3] << 24) | (wv[2] << 16) | (wv[1] << 8) | wv[0];
- }
-
- static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
- {
- wv[3] = v >> 24;
- wv[2] = v >> 16;
- wv[1] = v >> 8;
- wv[0] = v;
- }
-};
-
-template<>
-class Swap_unaligned<32, true>
-{
-public:
- typedef Valtype_base<32>::Valtype Valtype;
-
- static inline Valtype
- readval_unaligned(const unsigned char* wv)
- {
- return (wv[0] << 24) | (wv[1] << 16) | (wv[2] << 8) | wv[3];
- }
-
- static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
- {
- wv[0] = v >> 24;
- wv[1] = v >> 16;
- wv[2] = v >> 8;
- wv[3] = v;
- }
-};
-
-template<>
-class Swap_unaligned<64, false>
-{
-public:
- typedef Valtype_base<64>::Valtype Valtype;
-
- static inline Valtype
- readval_unaligned(const unsigned char* wv)
- {
- return ((static_cast<Valtype>(wv[7]) << 56)
- | (static_cast<Valtype>(wv[6]) << 48)
- | (static_cast<Valtype>(wv[5]) << 40)
- | (static_cast<Valtype>(wv[4]) << 32)
- | (static_cast<Valtype>(wv[3]) << 24)
- | (static_cast<Valtype>(wv[2]) << 16)
- | (static_cast<Valtype>(wv[1]) << 8)
- | static_cast<Valtype>(wv[0]));
- }
-
- static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
- {
- wv[7] = v >> 56;
- wv[6] = v >> 48;
- wv[5] = v >> 40;
- wv[4] = v >> 32;
- wv[3] = v >> 24;
- wv[2] = v >> 16;
- wv[1] = v >> 8;
- wv[0] = v;
- }
-};
-
-template<>
-class Swap_unaligned<64, true>
-{
-public:
- typedef Valtype_base<64>::Valtype Valtype;
-
- static inline Valtype
- readval_unaligned(const unsigned char* wv)
- {
- return ((static_cast<Valtype>(wv[0]) << 56)
- | (static_cast<Valtype>(wv[1]) << 48)
- | (static_cast<Valtype>(wv[2]) << 40)
- | (static_cast<Valtype>(wv[3]) << 32)
- | (static_cast<Valtype>(wv[4]) << 24)
- | (static_cast<Valtype>(wv[5]) << 16)
- | (static_cast<Valtype>(wv[6]) << 8)
- | static_cast<Valtype>(wv[7]));
- }
-
- static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
- {
- wv[7] = v >> 56;
- wv[6] = v >> 48;
- wv[5] = v >> 40;
- wv[4] = v >> 32;
- wv[3] = v >> 24;
- wv[2] = v >> 16;
- wv[1] = v >> 8;
- wv[0] = v;
- }
-};
-
// Standard relocation routines which are used on many targets. Here
// SIZE and BIG_ENDIAN refer to the target, not the relocation type.
// VALSIZE is the size of the value.
template<int valsize>
static inline void
- rel(unsigned char* view, typename Swap<valsize, big_endian>::Valtype value)
+ rel(unsigned char* view,
+ typename elfcpp::Swap<valsize, big_endian>::Valtype value)
{
- typedef typename Swap<valsize, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
- Valtype x = Swap<valsize, big_endian>::readval(wv);
- Swap<valsize, big_endian>::writeval(wv, x + value);
+ Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv);
+ elfcpp::Swap<valsize, big_endian>::writeval(wv, x + value);
}
// Do a simple PC relative relocation with the addend in the section
// contents. VALSIZE is the size of the value.
template<int valsize>
static inline void
- pcrel(unsigned char* view, typename Swap<valsize, big_endian>::Valtype value,
+ pcrel(unsigned char* view,
+ typename elfcpp::Swap<valsize, big_endian>::Valtype value,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{
- typedef typename Swap<valsize, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
- Valtype x = Swap<valsize, big_endian>::readval(wv);
- Swap<valsize, big_endian>::writeval(wv, x + value - address);
+ Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv);
+ elfcpp::Swap<valsize, big_endian>::writeval(wv, x + value - address);
}
typedef Relocate_functions<size, big_endian> This;
// Do a simple 64-bit REL relocation with the addend in the section
// contents.
static inline void
- rel64(unsigned char* view, elfcpp::Elf_Word value)
+ rel64(unsigned char* view, elfcpp::Elf_Xword value)
{
This::template rel<64>(view, value);
}
// Do a simple 64-bit PC relative REL relocation with the addend in
// the section contents.
static inline void
- pcrel64(unsigned char* view, elfcpp::Elf_Word value,
+ pcrel64(unsigned char* view, elfcpp::Elf_Xword value,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{
This::template pcrel<64>(view, value, address);
}
};
+// We try to avoid COPY relocations when possible. A COPY relocation
+// may be required when an executable refers to a variable defined in
+// a shared library. COPY relocations are problematic because they
+// tie the executable to the exact size of the variable in the shared
+// library. We can avoid them if all the references to the variable
+// are in a writeable section. In that case we can simply use dynamic
+// relocations. However, when scanning relocs, we don't know when we
+// see the relocation whether we will be forced to use a COPY
+// relocation or not. So we have to save the relocation during the
+// reloc scanning, and then emit it as a dynamic relocation if
+// necessary. This class implements that. It is used by the target
+// specific code.
+
+template<int size, bool big_endian>
+class Copy_relocs
+{
+ public:
+ Copy_relocs()
+ : entries_()
+ { }
+
+ // Return whether we need a COPY reloc for a reloc against GSYM,
+ // which is being applied to section SHNDX in OBJECT.
+ static bool
+ need_copy_reloc(const General_options*, Relobj* object, unsigned int shndx,
+ Sized_symbol<size>* gsym);
+
+ // Save a Rel against SYM for possible emission later. SHNDX is the
+ // index of the section to which the reloc is being applied.
+ void
+ save(Symbol* sym, Relobj*, unsigned int shndx,
+ const elfcpp::Rel<size, big_endian>&);
+
+ // Save a Rela against SYM for possible emission later.
+ void
+ save(Symbol* sym, Relobj*, unsigned int shndx,
+ const elfcpp::Rela<size, big_endian>&);
+
+ // Return whether there are any relocs to emit. This also discards
+ // entries which need not be emitted.
+ bool
+ any_to_emit();
+
+ // Emit relocs for each symbol which did not get a COPY reloc (i.e.,
+ // is still defined in the dynamic object).
+ template<int sh_type>
+ void
+ emit(Output_data_reloc<sh_type, true, size, big_endian>*);
+
+ private:
+ typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
+ typedef typename elfcpp::Elf_types<size>::Elf_Addr Addend;
+
+ // This POD class holds the entries we are saving.
+ class Copy_reloc_entry
+ {
+ public:
+ Copy_reloc_entry(Symbol* sym, unsigned int reloc_type,
+ Relobj* relobj, unsigned int shndx,
+ Address address, Addend addend)
+ : sym_(sym), reloc_type_(reloc_type), relobj_(relobj),
+ shndx_(shndx), address_(address), addend_(addend)
+ { }
+
+ // Return whether we should emit this reloc. If we should not
+ // emit, we clear it.
+ bool
+ should_emit();
+
+ // Emit this reloc.
+
+ void
+ emit(Output_data_reloc<elfcpp::SHT_REL, true, size, big_endian>*);
+
+ void
+ emit(Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian>*);
+
+ private:
+ Symbol* sym_;
+ unsigned int reloc_type_;
+ Relobj* relobj_;
+ unsigned int shndx_;
+ Address address_;
+ Addend addend_;
+ };
+
+ // A list of relocs to be saved.
+ typedef std::vector<Copy_reloc_entry> Copy_reloc_entries;
+
+ // The list of relocs we are saving.
+ Copy_reloc_entries entries_;
+};
+
} // End namespace gold.
#endif // !defined(GOLD_RELOC_H)
projects / deliverable / binutils-gdb.git / blobdiff